Thursday, July 30, 2020

Solar System Missions Update 2020-08

Here's my map of all active and future Solar System Missions as of August 1st 2020.

Go Perseverance! Go Al Amal! Go Tianwen! They're on their way now, and will arrive at Mars in February 2021.

OSIRIS-REx will rehearse the sample retrieval operation one last time on the 11th before opefully going for the real thing in October.

Data, images and documentation are available on my space exploration history GitHub repository and the associated website.

Tuesday, June 30, 2020

Solar System Missions Update 2020-07

Here's my map of all active and future Solar System Missions as of July 1st 2020.

Parker Solar Probe is headed for its third Venus flyby on the 11th which will further lower its perihelion to 0.095 AU. Meanwhile, Juno has the 28th perijove on the 25th.

But the big ticket item happens on Earth, where the fleet of Mars missions are in full mating season right now (to their lauchers, get it?) for launches in July or early August. The current expected launch dates are the 14th for Al Amal, the 22nd for Perseverance and the 23rd for Tianwen-1

Data, images and documentation are available on my space exploration history GitHub repository and the associated website.

Wednesday, June 10, 2020

Milky Way Halo Update

Here are some new data for my Milky Way halo page based on recent analyses of the Gaia DR2 releaae.


Some recent papers (see below) present Gaia-based evidence for several groups of globular clusters that came with their progenitor galaxies which were captured by the Milky Way. Apart from the already known Sagittarius and Gaia-Enceladus dwarf galaxies there are now Seqoia, a dwarf accreted about 10 Gyr ago, Omega Cen may be the its former nucleus. 21 associated GCs came from the somewhat larger Koala according to Forbes et al.(2020), as well as the Helmi stream, which may have been accreted 5 to 8 Gyrs ago. The number of 76 cluster between those 5 galaxies represent a significant fraction of the total for the Milky Way. 184 are known at the moment, some of the others also show characteristics of accretion but can not be associated with a known progenitor.

Krujissen et al. (2018) The formation and assembly history of the Milky Way revealed by its globular cluster population. arXiv:astro-ph/1806.05680v2
Massari et al. (2019)Origin of the system of globular clusters in the Milky Way. arXiv:astro-ph/1906.08271v2
Marsakov et al. (2020) Globular Clusters of the Galaxy: Chemical Composition vs Kinematics. arXiv:astro-ph/2002.10692v1
Forbes et al. (2020) Reverse engineering the Milky Way. arXiv:astro-ph/2002.01512v1

Wednesday, June 3, 2020

D3-Celestial: Automatic Time Zone Setting

Another new feature for D3-Celestial: Automatic time zone setting, thanks to TimeZoneDB , which provides an easy unterface to get the current time zone for any location on earth. The only limitation for a free account is a maximum of one request per second. So if you want to use it, I suggest register for your own account on that sevice. If you do, put your account ID in the config under 'timezoneid', if you don't want the time zone changed automatically, set 'settimezone' to false.

Saturday, May 30, 2020

Solar System Missions Update 2020-06

Here's my map of all active and future Solar System Missions as of June 1st 2020.

On the 7th Parker Solar Probe will have its fifth perijelion at 0.13 AU distance. A bit further out Solar Orbiter has its first perihelion on the 15th, while it is still busy flying through the tail of comet C/2019 Y4 ATLAS at the beginnig of the month. Even further out Juno has the 27th perijove on the 2nd.

The Mars missions Perseverance, Al Amal and Tianwen-1 all remain on track for a launch in July or early August.

Data, images and documentation are available on my space exploration history GitHub repository and the associated website.

Thursday, May 14, 2020

D3-Celestial: SVG and PNG-Export

A long requested feature for D3-Celestial: Export a map view as SVG, and for good measure I also implemented saving a PNG image. Both are available as buttons below the form. Ther isn't much to write about; a simple click saves the current view in the chosen format. the configuration parameter formFields.download = true enables the feature.

Tuesday, May 12, 2020

D3-Celestial: Better DSO Names

Now here is the final naming feature for D3-Celestial: Deep Space Objects (DSOs), again thanks to Stellarium, which provides names and translations for many DSOs through their fantastic sky cultures feature, already providing thranslations in many languages. With this it made sense to separate the names from the data, and put them in a common file named dsonames.json that is indexed by the most commn designator for each object, e.g. NGC 224 (the Andromade Galaxy) of M 45 (Pleiades).